Pros
Almost none...aside from gaining valuable experience to use for your next job hunt. They do have enough variety in customers and systems that you will get your hands on quite a few different systems to gain knowledge and hands-on experience.
Cons
Horrific project planning, go on-site to deploy a solution only to find the owners who hold the keys to the castle didn't enable all the accounts you need. You don't have access to do it yourself. Everything is "just wing it." No customer site documentation, you do what you can to triage each incident, but you have to record where you spend your time meticulously to track "billable hours" so you can't spend time just making network diagrams and documenting to help yourself next time. You have to fix whatever is wrong as fast as you can, then move on...know it's going to be the same exact fire drill next time. On call was ridiculous. If it's your week, prepare to be woken up every single night with either false alarms or someone else's alarms because they missed it. Escalation was On-Call tech, then EVERYONE, so everyone wakes up even if it's not their week if someone misses an alert. Same problem here, 2am and there's a problem, but the owners don't share the passwords to the hosted systems so you can't even look to troubleshoot. No flexibility. They didn't care if you were up from midnight to 6am for an on-call event, they still expected you there at 8am, and didn't offer you an opportunity to leave early. Not even so much as a "thanks". Extremely high pressure, fear of making mistakes but no real guidance or training on anything. You are just thrown into the deep end, sink or swim. Owners would not have your back if something went wrong, I saw them throw other engineers under the bus to a customer blaming that engineer when it was actually lack of project planning and lack of any type of structured game plan that caused the problem. Promised to match my previous company salary during initial job offer, then after I gave my two weeks at my previous job they told me what my salary would be. It was significantly less than a "match".